Ipto speed limiting control valve

ABSTRACT

Pressure is sensed in the multiple control valve of the IPTO assembly. By hydraulic means the pressure variations are communicated to a hydraulic piston which, via a linkage assembly, modifies the work cycle of the engine governor.

United States Patent Hale [ Apr. 2, 1974 IPTO SPEED LIMITING CONTROLVALVE [75] Inventor: Richard A. Hale, Downers Grove,

lll.

[73] Assignee: International Harvester Co.,

Chicago, Ill.

[22] Filed: Jan. 8, I973 21 Appl. No.: 321,908

[52] U.S. Cl 192/.084, 192/.096, 192/.098 [51 Int. Cl B60k 25/00 [58]Field of Search 192/.084, .096, .098;

[56] References Cited UNITED STATES PATENTS Maynard -l92/.096 X2,505,447 4/1950 Wemp l92/.()84 2,115,125 4/1938 Sinclair 192/.096

FOREIGN PATENTS OR APPLICATIONS 640,599 7 1950 Great Britain l92/.()84

Primary Examiner-Samuel Scott Assistant Examiner-Lance W. ChandlerAttorney, Agent, or FirmJohn A. Sehaerli; Floyd B. Harman [57] ABSTRACTPressure is sensed in the multiple control valve of the [PTO assembly.By hydraulic means the pressure variations are communicated to ahydraulic piston which, via a linkage assembly, modifies the work cycleof the engine governor.

5 Claims, 2 Drawing Figures IPTO SPEED LIMITING CONTROL VALVE Thisinvention relates to independent power take-off shafts and moreparticularly to a device responsive to the actuation of the IPTO shaftthat in turn control the speed of the engine driving the IPTO shaft.

tion and are familiar and well known in the industry.

. The engine governor means 16 for example controls In the normal casewhere a vehicle such as a tractor is fitted with an IPTO assembly, thespeedor RPM of the [PTO shaft is directly dependent upon the speed orRPM of the engine. For the most part force is transferred from thetractor engine to the [PTO assembly by a direct gear assembly. Itsometimes is necessary or desirable to increase the RPM of the enginewhich runs the lPTO assembly as a result of increasing tractor drawbarhorsepower for example. If this is done and the IPTO driving gears arenot replaced to correspond to the new engine speed, the lPTO shaft wouldrotate at more than the standard 540 and 1000 RPM. Often these speedsexceed a safe or desirable speed of operation of the driven implement.As a result, it is desirable to govern the speed of the engine in directresponse to the speed of the IPTO shaft when the latter is engaged. Itis therefore an object of this invention to provide a means forassociation with a standard engine governor to prevent excessive lPTOshaft speeds. Yet another object of this invention is to provide a meansof sensing hydraulic pressure in an lPTO shaft assembly.

Still another object of this invention is to provide an engine RPMlimiting device which operates only when the [PTO assembly is actuated.In accordance with the invention a governed engine is used to drive anlPTO assembly. The governor of the engine is made responsive to theactuation of the IPTO, that is the governor is arrested when the speedof the lPTO shaft reaches apredetermined level. A hydraulic limitingmeans isemployed to sense pressure in the [PTO assembly and translatethispressure into force which via a mechanical linking assembly controlsthe degree of actuation of the engine governor.

Other objects and advantages of the invention will become apparent uponreading the following detailed description and upon reference to thedrawings, in

which: v r

FIG. 1 is an outline view of an engine, transmission housing, and; lPTOassembly illustrating the relative positions thereon of theseveralelements employed in the practice of the present invention, and

FIG. 2 is an enlarged cross-sectional viewof the hydrualic cylindermeans which responds to pressure in the IPTO assembly.

While the invention will be described in connection with a preferredembodiment, it will be understood that it is not intended to limit theinvention to that embodiment. On the contrary, it is intended to. coverall alternatives, modifications, and equivalences as may be includedwithin the spirit and scope of the invention as defined by the appendedclaims.

Turning now to the drawings and more particularly to FIG. 1 wherein isshown an engine mounted in a vehicle (not shown). Rearwardly of theengine means 10 is a transmission assembly 12 and rearwardly thereof anlPTO assembly means 14. Situated forwardly on the engine means 10 isanengine governor means 16. Similarly associated with IPTO assembly means14 is a multiple control valve means 18 and IPTO control spool means 20andan IPTO shaft means 22. All of these components are of standardconstructhe fuel injection pump when a diesel engine is used andcontrols the carburetor when a gas engine is employed. The multiplecontrol valve 18 contains a power chamber actuated by lines connectedwith the tractors or vehicles hydraulic system (not shown), highpressure fluid being admitted thereto for compressing the clutch platesby the manipulation of [PTC control spool means 20. The construction andfunction of these elements are incidental to the present invention andtherefore have not been shown or discussed in great detail.

Said fluid communication with the high pressure fluid contained inmultiple control valve'l8 is established by port 24. By such fluidcommunication it is possible to sense pressure in the multiple controlvalve. That is upon admission of high pressure fluid to the powerchambers (not shown) to force together the clutch plates (not shown) ofthe [PTO shaft means 22 high pressure'fluid becomes available. The highpressure fluid is transferred through conduit means 26 to hydrauliccylinder sensing means 28 whereby fluid communication is establishedtherebetween.

The engine governor means 16 is geared or otherwise suitably attached toa throttle means (not shown) losembly; that is, any movement of enginegovernor l6 is immediately transferred to governor control means 30 andvisa versa. In the preferred embodiment the mechanical linkage means 32therebetween is an elongated member of unitary construction.

In referring now to FIG. 2 wherein is more clearly shown governorcontrol bell crank 30 and hydraulic cylinder sensing means 28. As showntherein governor control 30 in position A corresponds to an engine speedwhich produces an IPTO speed of 540 RPM. That is the operator hasactuated the throttle member (not shown). on the dash (not shown) andmoved engine governor 16 to a position such that governor control bellcrank 30 assumes position A. Correspondingly phantom position Brepresents an engine idle position and. phantom position C would if notfor the invention herein disclosed correspond to a high engine speed. Aswill be more fully explained here after the lPTO hydraulic limitingdevice 23 includes the hydraulic cylinder means 28, mechanical linkage32, control bell crank 30 and conduit means 26.

The hydraulic cylinder sensing means 28, also shown in FIG. 2, includesa housing means 34 having a bore means 36 therein. The bore means 36 hasa first opening means 38 for the admission and exiting of high pressurefluid, and a second opening means 40 through which piston means 42 movesin a reciprocating manner. As is apparent, upon the actuation of theIPTO clutch (not shown) high pressure fluid is communicated for multiplecontrol valve 18 via conduit means 26 to bore means 36 wherein ahydraulic power chamber means 44 is formed, causing the reciprocativemovement of piston means 42. As is shown in FIG. 2 the extension ofpiston means 42 prevents the movement of governor control means 30 intophantom posi-.

tion C. The end means 46 thereof physically contacting the surface 48 ofgovernor control means 30. The hydraulic cylinder means 28 is carried orotherwise supported by a bracket or support means 50 such that hydrauliccylinder means 28 can move with respect thereto in a reciprocatingmanner. In the preferred embodiment the surface 52 of housing 34 has athreaded means 54. A first and second jam nut means 56 and 58 are thenthreadedly secured on thread means 54 such that the bracket or supportmeans 50 carries the hydrualic cylinder means. Thus, simply by movingthe relative positions of the jam nut means 56 and 58 it is possible tochange the relationship of the hydraulic cylinder means 28 to thebracket or support means 50.

In actual operation the RPM of the IPTO shaft means 22 are measured byany of number of suitable standard means. The engine via the throttlemeans (not shown) via engine governor means 16 is increased in speeduntil the [PTO shaft means 22 achieves a speed of 540 RPM. Under theseconditions, which may vary from vehicle to vehicle, the governor'controlbell crank means 30 will because of mechanical linkage 32 havingfollowed engine governor means l6 and thereby assumed a position such asA shown in FIG. 2. Under these conditions the hydraulic cylinder means28 is positioned in its support means 50 and secured such that end 46 ofpiston means 42 is in close proximity or touching surface 48 of bellcrank 30. After this initial setting whenever the IPTO assembly 14 isactuated piston means 42 will return to substantially the same setposition. Thus, if the engine is operating at a high speed, such ascorresponding to phantom position C in FIG. 2, upon engagement of theIPTO assembly 14 piston means 42 will force governor control 30 into aposition corresponding to position A and consequently decrease the speedof the engine. Correspondingly if the IPTO assembly trol means 30 is inposition B and thereafter accelerated toward a position corresponding toC, piston means 42 will arrest the engine governor 16 at an engine speedcorresponding to an lPTO speed of 540 RPM. The [FTC speed limitingdevice means 23 will only regulate the engine governor means 16 when the[PTO shaft means is engaged; at other times, it remains out of contacttherewith. v

Thus it is apparent that there has been provided in accordance with theinvention an IPTO speed limiting device that fully satisfies theobjects, aims and advantages set forth above. While the invention hasbeen described in conjunction with specific embodimetns thereof, it isevident that many alternatives, modifica- 14 is engaged when thegovernor con-- tions, and variations will be apparent to those skilledin the art. in light of the foregoing description. Accordingly, it isintended to embrace all such alternatives, modifications, and variationsas fall within the spirit and broad scope of the appended claims. Whatis claimed is: I

1. An engine means driving an IPTO assembly means which is engaged anddisengaged by a multiple control valve carried thereon, a governor meanson said engine made responsive to the actuation of said IPTO by ahydraulic limiting means comprising:

a hydraulic cylinder means, a bell crank lever means adjacent saidhydraulic cylinder means, a linking means fluidly'communicating saidcontrol valve and said hydraulic cylinder means,

a mechanical linkage means connecting said gover nor means and said bellcrank lever means whereby force is transferred therebetween, such thatsaid 7 governor means is subject to limiting only when said IPTO isengaged.

2. The hydraulic limiting means of claim 1 wherein said hydrualiccylinder means includes a housing means having a power chamber meanstherein, and a support means reciprocatively carrying said housingmeans.

3. The hydraulic limiting means of claim 2 wherein said housing meanscarries a piston means reciprocatively therein, whereby said pistonlimits the degree of travel of said bell crank lever means.

4. The hydraulic limiting means of claim 3 wherein said multiple controlvalve means carries hydraulic fluid whereby the pressurization of saidfluid is dependent upon actuation of said IPTO assembly.

5. An engine means driving an IPTO assembly means which is engaged anddisengaged by a multiple control valve carried thereon, a governor meanson said engine made responsive to' actuation of said [PTO by a hydrauliclimiting means comprising:

a hydraulic cylinder means having a housing which includes a powerchamber means and a piston means reciprocatively extending outtherefrom,

I a linking means fluidly communicating said multiple control valvemeans and said power chamber whereby upon actuation of said IPTOassembly pressurized fluid flows into said power chamber, and e I alinking means responding to movement of said governor, the travelthereof being subject to control by said piston. 1 v

1. An engine means driving an IPTO assembly means which is engaged anddisengaged by a multiple control valve carried thereon, a governor meanson said engine made responsive to the actuation of said IPTO by ahydraulic limiting means comprising: a hydraulic cylinder means, a bellcrank lever means adjacent said hydraulic cylinder means, a linkingmeans fluidly communicating said control valve and said hydrauliccylinder means, a mechanical linkage means connecting said governormeans and said bell crank lever means whereby force is transferredtherebetween, such that said governor means is subject to limiting onlywhen said IPTO is engaged.
 2. The hydraulic limiting means of claim 1wherein said hydrualic cylinder means includes a housing means having apower chamber means therein, and a support means reciprocativelycarrying said housing means.
 3. The hydraulic limiting means of claim 2wherein said housing means carries a piston means reciprocativelytherein, whereby said piston limits the degree of travel of said bellcrank lever means.
 4. The hydraulic limiting means of claim 3 whereinsaid multiple control valve means carries hydraulic fluid whereby thepressurization of said fluid is dependent upon actuation of said IPTOassembly.
 5. An engine means driving an IPTO assembly means which isenGaged and disengaged by a multiple control valve carried thereon, agovernor means on said engine made responsive to actuation of said IPTOby a hydraulic limiting means comprising: a hydraulic cylinder meanshaving a housing which includes a power chamber means and a piston meansreciprocatively extending out therefrom, a linking means fluidlycommunicating said multiple control valve means and said power chamberwhereby upon actuation of said IPTO assembly pressurized fluid flowsinto said power chamber, and a linking means responding to movement ofsaid governor, the travel thereof being subject to control by saidpiston.